(e) not to revoke the Lessee Power of Attorney; and

 (f) to cause the following:

 (i) the filing of a Spanish language Public Deed with
 respect to the Bill of Sale, the Trust Agreement, this
 Agreement and Lease Supplement No. 1 at the Public
 Registry of Panama within 48 hours after the date and
 time of Delivery;

 (ii) the obtaining of a temporary `certificado de matricula'
 from the National Aeronautic Registry of the Civil
 Aviation Authority of Panama with respect to the
 Aircraft at or before Delivery;

 (iii) the obtaining of a permanent `certificado de matricula'
 from the National Aeronautic Registry of the Civil
 Aviation Authority of Panama promptly, and in any event
 within 45 days after Delivery; and

 (iv) promptly and in due course after Delivery, a Public
 Registry Certificate confirming registration of the
 Public Deed referred to in the preceding clause (i).

 8.12 MAINTENANCE AND REPAIR:

 Lessee will, at its own expense:

 (a) keep the Aircraft airworthy (except during any period during
 which the Aircraft is undergoing maintenance, repair or
 modification as required or permitted hereunder) in all
 respects and in good repair and condition;

 (b) not change the Approved Maintenance Program without all
 necessary approvals from the Air Authority; provided, however,
 that if any such

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